Voltage control with feedback utilizing analog and digital control signals

摘要

An output voltage control apparatus for performing feedback control on an output voltage of an inverter which drives an AC machine. The output voltage control apparatus converts a command value for the output voltage of the inverter into a pulse density using a converter (PDM), and converts a detection value of the output voltage of the inverter into a pulse density using a DELTA - SIGMA modulation converter. The proportional control ability and integral control ability for the output voltage are realized by digital hardware including an up-counter, a down-counter and a shift circuit.